Probabilistic approaches for investigating species co-occurrence from presence-absence maps.

Background: In this research, we propose probabilistic approaches to identify pairwise patterns of species co-occurrence by using presence-absence maps only. In particular, the two-by-two contingency table constructed from a presence-absence map of two species would be sufficient to compute the test statistics and perform the statistical tests proposed in this article. Some previous studies have investigated species co-occurrence through incidence data of different survey sites. We focus on using presence-absence maps for a specific study plot instead. The proposed methods are assessed by a thorough simulation study. Methods: A Chi-squared test is used to determine whether the distributions of two species are independent. If the null hypothesis of independence is rejected, the Chi-squared method can not distinguish positive or negative association between two species. We propose six different approaches based on either the binomial or Poisson distribution to obtain p-values for testing the positive (or negative) association between two species. When we test to investigate a positive (or negative) association, if the p-value is below the predetermined level of significance, then we have enough evidence to support that the two species are positively (or negatively) associated. Results: A simulation study is conducted to demonstrate the type-I errors and the testing powers of our approaches. The probabilistic approach proposed by Veech (2013) is served as a benchmark for comparison. The results show that the type-I error of the Chi-squared test is close to the significance level when the presence rate is between 40% and 80%. For extremely low or high presence rate data, one of our approaches outperforms Veech (2013)'s in terms of the testing power and type-I error rate. The proposed methods are applied to a tree data of Barro Colorado Island in Panama and a tree data of Lansing Woods in USA. Both positive and negative associations are found among some species in these two real data.

Effects of different gastrointestinal reconstruction techniques on nutrition, anemia, and quality of life in laparoscopic distal gastrectomy for gastric cancer.

PURPOSE: To explore the effect of different gastrointestinal reconstruction techniques on laparoscopic distal gastrectomy of gastric cancer on the nutritional and anemia status, and quality of life (QoL) of patients. METHODS: Eligible patients were randomly divided into three groups (n=36/group): Billroth I anastomosis group, Billroth II combined with Braun anastomosis group, and Roux-en-Y anastomosis group. Related indicators were compared and analyzed. RESULTS: The general data were comparable among the three groups (all P>0.05). Among the surgical-related indicators and postoperative recovery indicators, only the comparison of the operation time was statistically significant (P=0.004). The follow-up time was 5~36 months (average 27.9 months). In terms of nutritional and anemia indicators, only the differences in the levels of prealbumin, hemoglobin and serum ferritin in 24 months after operation showed significant differences (P=0.015, P=0.003, P=0.005, respectively). There were no significant differences in hospital readmission rate, overall survival, and QoL among the three groups (all P>0.05). CONCLUSIONS: In laparoscopic gastrectomy for stage II~III distal gastric cancer, Billroth I anastomosis has shorter operation time than Billroth II combined with Braun anastomosis and Roux-en-Y anastomosis and advantages in the improvement of nutritional status and anemia recovery.

Effects of different gastrointestinal reconstruction techniques on nutrition, anemia, and quality of life in laparoscopic distal gastrectomy for gastric cancer

Purpose: To explore the effect of different gastrointestinal reconstruction techniques on laparoscopic distal gastrectomy of gastric cancer on the nutritional and anemia status, and quality of life (QoL) of patients. Methods: Eligible patients were randomly divided into three groups (n=36/group): Billroth I anastomosis group, Billroth II combined with Braun anastomosis group, and Roux-en-Y anastomosis group. Related indicators were compared and analyzed. Results: The general data were comparable among the three groups (all P>0.05). Among the surgical-related indicators and postoperative recovery indicators, only the comparison of the operation time was statistically significant (P=0.004). The follow-up time was 5~36 months (average 27.9 months). In terms of nutritional and anemia indicators, only the differences in the levels of prealbumin, hemoglobin and serum ferritin in 24 months after operation showed significant differences (P=0.015, P=0.003, P=0.005, respectively). There were no significant differences in hospital readmission rate, overall survival, and QoL among the three groups (all P>0.05). Conclusions: In laparoscopic gastrectomy for stage II~III distal gastric cancer, Billroth I anastomosis has shorter operation time than Billroth II combined with Braun anastomosis and Roux-en-Y anastomosis and advantages in the improvement of nutritional status and anemia recovery.

Effects of Statins for Secondary Prevention on Functioning and Other Outcomes Among Nursing Home Residents.

OBJECTIVES: Studies examining the effects of statins after acute myocardial infarction (AMI) excluded frail older adults, especially nursing home (NH) residents, and few examined functional outcomes. Older NH residents may benefit less from statins and be particularly susceptible to adverse drug events like myopathy-related functional decline. We evaluated the effects of statins on 1-year functional decline, rehospitalization, and death in NH residents. DESIGN: We conducted a retrospective cohort study using 2007-2010 linked national data from Minimum Data Set (MDS) assessments, Medicare claims, and Online Survey Certification and Reporting System records. SETTING AND PARTICIPANTS: We included US NH residents 65 years and older who were statin nonusers, were hospitalized for AMI between May 2007 and March 2010, and returned to the NH. MEASURES: Outcomes were functional decline, death, and rehospitalization in the first year after post-AMI NH admission. New statin users were 1:1 propensity-score matched to nonusers to adjust for 92 characteristics. We estimated hazard ratios (HRs) and restricted mean survival time differences with 95% confidence intervals (CIs) comparing individuals who did vs did not initiate statin therapy after AMI hospitalization. RESULTS: Propensity-score matching yielded a cohort of 5440 residents. Mean age was 83 years and 69% were female. Statin use was associated with a reduction in mortality (HR 0.80, 95% CI 0.73-0.87), corresponding to a mean of 15.9 (95% CI 9.9-22.0) days of extended life expectancy. No overall differences in rehospitalization (HR 1.06, 95% CI 0.98-1.14) or functional decline (HR 1.00, 95% CI 0.88-1.14) were observed. CONCLUSIONS AND IMPLICATIONS: Statins may reduce 1-year mortality by 20% without affecting function among older NH residents who wish to live longer after AMI. During shared decision making with these patients or their representatives, clinicians should consider communicating that the average benefit of statins is 16 days of additional survival over 1 year.

Predicting the progress of colon cancer by DNA methylation markers of the p16 gene in feces - Evidence from an animal model.

A new noninvasive screening tool for colorectal neoplasia detects epigenetic alterations exhibited by gastrointestinal tumor cells shed into stool. There is insufficient existing data to determine temporal associations between colorectal cancer (CRC) progression and aberrant DNA methylation. To evaluate the feasibility of using fecal DNA methylation status to determine CRC progression, we collected stool samples from 14 male SD rats aged six weeks, and administered subcutaneous injections of either 1,2-dimethylhydrazine or saline weekly. p16 DNA methylation statuses in tumorous and normal colon tissue, and from stool samples were determined using methylation-specific PCR. Additionally, p16 methylation was detected in stool DNA from 85.7% of the CRC rats. The earliest change in p16 methylation status in the DMH-treated group stool samples occurred during week nine; repeatabilities were 57.1% in week 19 (p = 0.070) and 85.7% in week 34 (p = 0.005). A temporal correlation was evidenced between progression of CRC and p16 methylation status, as evidenced by DMH-induced rat feces. Using fecal DNA methylation status to determine colorectal tissue methylation status can reveal CRC progression. Our data suggests that p16 promoter methylation is a feasible epigenetic marker for the detection and may be useful for CRC screening.

Comparison of prognosis by viral etiology in patients with hepatocellular carcinoma after radiofrequency ablation.

UNLABELLED: BACKGROUND; Radiofrequency ablation (RFA) has been performed as a first line curative treatment modality for patients with hepatocellular carcinoma (HCC) within the Milan criteria currently. However, prognosis of hepatitis B- and hepatitis C-related HCC after RFA remains debatable. This study aimed to assess the impact of viral etiology on the prognosis of HCC patients undergoing RFA. MATERIAL AND METHODS: One hundred and ninety-two patients with positive serum HBV surface antigen (HBsAg) and negative serum antibody against HCV (anti-HCV) were enrolled as the B-HCC group and 165 patients with negative serum HBsAg and positive anti-HCV as the C-HCC group. Post-RFA prognoses were compared between the two groups using multivariate and propensity score matching analyses. RESULTS: The B-HCC group had higher male-to-female ratio and better liver functional reserve than the C-HCC group. After a median follow-up of 23.0 ± 22.7 months, 55 patients died and 189 patients had tumor recurrence after RFA. The cumulative five-year survival rate was 75.9% and 69.5% in the B-HCC and C-HCC groups, respectively (p = 0.312), while the five-year recurrence-free survival rate was 19.0% and 26.6%, respectively (p = 0.490). After propensity-score matching, the B-HCC group still had comparable overall survival rate (p = 0.679) and recurrence-free survival rate (p = 0.689) to the C-HCC group. For 132 patients with Barcelona-Clinic Liver Cancer stage 0, the five-year overall survival and recurrence-free survival rates were also comparable between the two groups (p = 0.559 and p = 0.872, respectively). CONCLUSION: Viral etiology is not essential for determining outcome in HCC patients undergoing RFA.

Global invasion history of the fire ant Solenopsis invicta.

The fire ant Solenopsis invicta is a significant pest that was inadvertently introduced into the southern United States almost a century ago and more recently into California and other regions of the world. An assessment of genetic variation at a diverse set of molecular markers in 2144 fire ant colonies from 75 geographic sites worldwide revealed that at least nine separate introductions of S. invicta have occurred into newly invaded areas and that the main southern U.S. population is probably the source of all but one of these introductions. The sole exception involves a putative serial invasion from the southern United States to California to Taiwan. These results illustrate in stark fashion a severe negative consequence of an increasingly massive and interconnected global trade and travel system.

Opiniones y actitudes de los obstetras de ciudad de la Habana, Cuba, en relación al uso de la cesárea / Opinions and attitudes of obstetricians city of Havana, Cuba, regarding the use of cesarean

Cada vez se observa con más frecuencia una tendencia mundial hacia el crecimiento en las tasas de cesáreas, y Cuba no es la excepción. Objetivos: determinar las causas del aumento de las tasas de cesáreas en la Ciudad de la Habana, e identificar las posibles intervenciones que pudieran detener dicha tendencia; así como las preferencias de los obstetras cuando enfrentan ciertas situaciones clínicas. Metodología: se realizó un estudio descriptivo y exploratorio, para lo cual se administró un cuestionario anónimo a 132 obstetras que laboran en 5 hospitales maternos de la Ciudad de la Habana...